function y = arwhead(x)
%    ARWHEAD  (CUTE)  Function   
%x0= [1.,1.,...,1.]..  
%fmin=n/2,m=20
%Author:shi yangyang
n=length(x);
y=ones(1,n-1);
for i=1:n-1
    y(i)=(-4.0*x(i)+3.0) + (x(i)^2+x(n)^2)^2;
end
y=sum(y);